This research project is examining the hypothalamic mechanisms that control and regulate ingestive behavior in rodents. The nature of the functional disorders underlying the hyperphagia and aphagia syndromes are being investigated by analyzing the effects of hypothalamic knife cuts on the short- and long-term regulation of food intake, water intake, and body weight. A dual lipostat model of hunger and appetite is being tested. The effects of hypothalamic damage on the diurnal patterns of feeding and locomotor activity is also under investigation.